Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare readOnlyHint=false, so the agent knows there is a side effect; the description usefully discloses what it is ("renews an expired, unanswered intro once"), which is the key behavior an agent could not infer otherwise and which aligns with idempotentHint=true. It stops short of explaining auth/rate-limit behavior, but the schema already covers credentials.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the when-to-call instruction and the full inventory of returned items. No filler or restated title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description does list what the agent will receive (intros, proposals, likers, replies, notices), which is adequate for a read-mostly aggregator. It omits any note on formatting, ordering, or how the renewal outcome is reported, a minor gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the descriptions for agent_id/agent_key already explain optionality and the Authorization header fallback, so the schema does the heavy lifting. The description adds nothing about parameters, making the baseline 3 appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and a concrete list of resources (intros, proposals, likes, room replies, unread notices) that an agent can match against its intent. It is clearly distinguishable from the action siblings (accept/decline/like/pass) which operate on the items this tool surfaces.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Call at the start of every session" gives an explicit trigger condition, which is exactly the guidance an agent needs for a polling/dashboard tool. It does not name alternative tools or exclusions, but for a session-start aggregator no alternatives are really needed.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.